Functional Analysis of MiZAT10A and MiZAT10B Genes in Mango

Zinc finger protein (ZFP) plays an important role in plant abiotic stress response. Therefore, to provide a theoretical basis for stress resistance breeding, this study aimed to analyze the response of two zinc finger protein genes of MiZAT10A and MiZAT10B transgenic Arabidopsis to abiotic stresses, such as salt, drought, heavy metals and exogenous hormones.

The promoter cis acting elements and motif of mango MiZAT10A and MiZAT10B genes were predicted and analyzed by online software PLACE and MEME, respectively. The chromosome location map was drawn by TBtools software and SiJiMi gene annotation file (GFF file and unpublished). Tissue expression patterns of MiZAT10A and MiZAT10B genes were analyzed by qRT-PCR. The overexpression vectors of MiZAT10A and MiZAT10B genes were constructed and transformed into Arabidopsis thaliana by Agrobacterium floral-dip method. The phenotype of MiZAT10A and MiZAT10B transgenic plant were observed and recorded under salt, drought, heavy metals, abscisic acid and gibberellin treatments.

Promoter cis element analysis showed that there were many light response elements, hormone response elements and abiotic stress response elements in the promoter region of MiZAT10A and MiZAT10B genes. Expression analysis showed that MiZAT10A and MiZAT10B were highly expressed in buds and flowers. 9 of MiZAT10A and 14 of MiZAT10B transgenic Arabidopsis strains were obtained. Overexpression of MiZAT10A and MiZAT10B significantly resulted early flowering compared with the control lines. The root length of MiZAT10A and MiZAT10B overexpressing transgenic Arabidopsis was significantly longer than that of control lines under salt stress, drought stress, heavy metal stress, GA₃ and ABA hormone treatments.

Overexpression of MiZAT10A and MiZAT10B not only promoted transgenic Arabidopsis flowering early but also improved salt, drought, heavy metals and exogenous hormones GA₃ and ABA resistance.